Amateur Radio operators in Hawaii kept National Weather Service (NWS) meteorologists and local emergency operations centers up to date on changing conditions and power outages, as Tropical Storm Flossie pounded parts of Hawaii and Maui counties July 29-30 with heavy rain and lightning. Radio amateurs organized a joint SKYWARN/ARES/RACES operation using eight VoIP and microwave-linked VHF and UHF repeaters from state and county RACES to serve the NWS, the Central Pacific Hurricane Center (CPHC) and state and county officials.

Clem Jung, KH7HO, opened a SKYWARN net from the NWS Honolulu office ham station the evening of July 29 to establish an operational plan. The net reconvened the next morning on the AllStar Link repeater system and on 7.088 MHz. ARES and RACES members also participated.

Over its 12 hours of activation, the net recorded 67 check-ins and reports from hams in all four Hawaii counties. Net control stations received reports from throughout the state via Amateur Radio as well as by cell phones and even social media. All reports were shared with CPHC meteorologists. Harvey Monomura, AH6JA, and others on East Hawaii provided ground observations of rain and lightning conditions to supplement what forecasters were seeing via radar and infrared satellite imaging. The state EOC and all four county EOCs monitored the SKYWARN reports. As the storm moved west, stations on Maui reported considerable lightning and rain, and even small hail, coupled with power outages. As the storm diminished, the CPHC gave the okay to close the SKYWARN NET late on July 30.

Meteorologists have not confirmed earlier unofficial accounts that the mass of the Mauna Kea and Mauna Loa volcanoes, with summits towering above 13,600 feet, combined with upper-level shear from the northwest, to split the storm in two. Emergency Coordinator Ron Hashiro, AH6RH, believes the tall volcanoes, combined with the mass of a third volcano, Mount Haleakala on Maui, to affect Flossie’s circular motion, causing it to further downgrade to a tropical disturbance. Unverified reports suggest the volcanoes also may have influenced Flossie’s moist air to deflect upward and raise the tops of the thunderclouds to heights approaching 60,000 feet above Maui, resulting in increased lightning activity.

“This cooperation between the SKYWARN net control stations and the NWS was fantastic,” said Jung. “This success was possible because emergency coordinators had worked previously with the Amateur Radio community that participated in this net.”

In August 2007, Hurricane Flossie, a powerful South Pacific cyclone, brought squalls and caused light damage in Hawaii.